Internal-combustion engine



C. B. KIRKHAM INTERNAL COMBUSTION ENGINE Oct. 14 1924. 1,511,672

c. B. KIRKHAM INTERNAL COMBUSTION ENGINE Filed May 13, 1918 7 Sheets-Sheet 2 F162. Se 135 52 5 7) 59 G5 121 354 24- 5 127 E se 111 6 152 I 152 5 I 51 65 A 2'7 58 112 -11 112' i?? Se 501 @A26 150 15o 24 0M ATTocm En.

oet. 14 1924. 1,511,672

C. B. KIRKHAM INTERNAL COMBUSTION ENGINE Filed May 13. 1918 7 Sheets-Sheet 3 I NVE-N Ton c; 14 1924. o t c. B. KIRKHAM INTERNAL COMBUSTION ENGINE Filed May 13, 1918 7 Sheets-Sheet 4 ,fl/fill,

INVENTOR- Cr-Arancb KIRKHAM.

ATTORNEY- Oct. 14 1924. 1,511,672

c. B. KIRKHAM INTERNAL COMBUSTION ENGINE Filed May 13, 1918 7 Sheets-Sheet 5 Flc-3.10.

AT-roHe-v,

Oct. 14 1924.

ATTO l2 N EY.

Oct. 14 1924. 1,511,672

C. B. KIRKHAM INTERNAL COMBUSTION ENGINE Filed May 13 1918 7 .ahets-Sheet 7 INvEN-roz.

CHAaLeaKunH/AM,

f W aff/l A-rTozNeY,

Patented Oct. 14, 1924.

UNITED STATES PATENT OFFICE.

CHARLES B. KIBXHAM, OF GARDEN CITY, NEW YORK, ASSIGNOB, BY MESNE AS- SIGNIENTS, T0 CURTISS AEROPLANE AND MOTOR COMPANY, INC., A CORPORA- 'rroN or NEW Yoan.

INTERNAL-COMBUSTIO'N ENGINE.

Application led lay 13, 1918. Serial No. 234,235.

To all 'wlwm it may concern Be it known that I, CHARLES B. KIRKHAM, a citizen of the United States, residing at Garden City, L. I., in the county of Nassau and State of New York, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines and particularly7 aeronautical motorsof the type set forth 1n my application Serial No. 181,238, filed July 18, 1917.

The object of my invention is a motor which possesses to a marked degree all of those c aracteristics essential in a successful aeronautical motor, i. e. maximum power per unit weight, maximum eiiiciency, pronounced reliability, and substantial durability.

An important feature of the present motor (also characteristic of the motor of the above mentioned application) is the anchoring of the cylinders securely in their operative position independently of the water jacket casings whereby all mechanical connections between the cylinders and the 'ackets are eliminated and the cylinder dies are unaffected by the expansion and contraction of the jackets. To this end I so assemble the arts and attach the cylinders directly to t e valve cage in such manner that they are maintained in spaced relation to the jacket casings throughout the length of the piston travel. By this construction and arrangement there is no tendency for the cylinder bodies to become distorted from their c lindrical shape by the radial and longitudlnal contraction and expansion of the jackets. This is es ially 1m ortant in the present motor whlch embo ies aluminum or aluminum alloy jackets whose coeicient of expansion is substantially eater than that of the steel forgings of which the cylinder bodies are made.

More specifically the cylinder bodies or liners are attached thru their heads directly to a valve cage member, with their lower ends freely suspended therefrom and immersed in the cooling medium. The bodies are thereby free from the usual longitudinal strains set up by the explosions of the gaseous charges, and the transfer of heat from the interior of the cylinder takes lace directly to the cooling fluid through tlie cylinder wall, no insulatin mechanical connecn tion being encountere Moreover the dimensions of the cylinder head or combustion chamber ma be varied (expanded) without necessitating a corresponding variation of the cylinder bore, or the combustion chamber walls ma be as thick as desired to give the required rigidity, without a corresponding increase in the thickness of the walls throughout the piston travel.

The water jackets may be attached to the crank case in any manner desired but are preferably formed integrally therewith to enhance the strength and rigidity. My improvements are illustrated as embodied in a V-motor but certain features thereof are equally applicable to other types. The cylinder liners are anchored in pockets provided in the valve cage, and each liner has an integral head formed slightly convex outwardly, whereby when the cylinder is driven home the convex head is flattened out and securely held against the bottom of the ocket. To further ensure a tightnoninsu ating joint between the head and bottom of the pocket, each cylinder head is preferably provided with a tightening stud which enters 4a correspondmg opening through the valve cage wall and receives a clam ing nut.

Anot er important feature, is the formation (in a eared down motor) of the reduction gear ciamber integrall with the crank case, whereby the u per bearings of the crank shaft and the ower bearings of the propeller are formed in one piece and the alignment of the propeller and crank shafts is assured at all times. Certain other features reside in the reduction gear drive and mounting and in the drivin and actuatin mechanism for the overhea valves, as wil hereinafter appear more fully.

Other features of my invention will be apparent uponan inspection of the accom- 1 and a lower half 2, the lower hal anying drawin which illustrate one emodiment thereo wherein;

Fig. 1 is a longitudinal sectional view of my motor showing certain of the parts in elevation,

Fig. 2 is an end view thereof showing certain of the parts in section,

Fig. 3 is a sectional view thru the crank case showing the assembly thereof,

Fig. 4 is a sectional view on the line 4 4 of Fig. 3.

Fig. 5 is a sectional view thru one of the crank shaft bearin Fig. 6 is a view of t e end closing plate or housing for the crank case,

Fig. 7 is a sectional view thereof,

Fig. 8 is a sectional view thru the valve cage and the cylinder illustrating the assembly thereof,

9 is a view similar to Fig. 8 showing` e parts in assembled position,

ig. 10 is a side view o the valve cage and cylinders, y

Fig. 11 is a plan view thereof,

Fig. 12 is a sectional view thru a pair of intake valves and o erating mechanism,

Fig. 13 is a detailed sectional view thru the valve cage illustrating the spark plug passages,

Fig. 14 is a transverse sectional view thru the cylinders and water jackets,

Fig. 15 is a sectional view thru the cam shafts and bearings,

Fig. 16 is a more or less diagrammatic view of the stem of power transmission from the cran' shaft, and

Fi 17 is a diagrammatic view illustrat- -ing e operation of the intermeshing cam shafts.

Referring to the drawings wherein like numerals refer to similar parts throughout, I have illustrated m invention as embodied in a motor of the Vvtype having two banks of cylinders disposed at an angle to each other in the usual manner.

The crank case comprises an u per half compris- 3 located in the lower part thereof, forme by the downwardly slo ing bottom end walls thereof as indicate in Fig. 1. The lower half 3 and the upper half 1 are provided with com lementar shoulders or fianges 4 whereby t e two ha ves may be securely fastened togsther. A drip pan 5 separates the crank sha and operatingparts from the oil sump and is carried bv a flange or shelf 6 formed integrally on the interior of the lower half, the pan 5 being suitably fixed thereto as for instance by the screw bolts indicated in Fig. 2. The lower half 2 of the crank case is also provided on one side thereof with an integrally formed intak p 7, the latter being in communication wit an lly formed chamber 8 on the upper hal of the crank case and ing an oil sum leading downwardly to the oil sump beneath the drip pan 5 as indicated in Fig. 2. The chamber 8 which is formed on the exterior of the side of the upper half may be provided with a suitable cover plate 9, the latter being securely held upon its seat by means of a bolt and spring 10. By means of this intake chamber 8 and the communicatinnr passage 7 lubricant may be supplied to the oil sump 3 when it is necessary to replenish the supply. The lower half of the crank case is also provided with the collecting chambers 11 and 12 at either end of the drip pan 5 at the ends of which is collected the used lubricant as it drains downwardly from the moving parts of the motor. From these collection chambers the used lubricant is drawn downwardly thru the communicating ducts 13 and 14 by means of a scavengin pump 15 and forced therefrom into the oil sump 3. The pump 15 also embodies in addition to the scaven'gin pump a force pump (this pump being set orth and claimed in a co-pending application) which forces the lubricant from the sump 3 out thru the duct 16, the latter leading upwardly on the exterior of the crank case and then transversely thru an opening formed therein to the downwardly extending duct 17. The duct 17 in turn leads downwardly to a distributing head or ipe 18 and the latter has a plurality of Eranch pipes leading upwardly to the bearings 20 of the crank shaft 21. Thru the medium of these lubricating ducts and the force pump 15, the crank shaft bearings of the motor may be supplied with lubricant in the usual manner.

In the specific embodiment illustrated there are provided two banks of cylinders with six cylinders in each bank, and in a manner similar to the construction of the motor set forth in the above noted application, the water jackets 22 for the cylinders being cast integral] with the upper half of the crank case. n the motor illustrated herein the water jackets are formed in pairs. each air enclosing a common cooling fluid cham r (Fig. 14?l for a pair of cylinders 25. It is a feature of t e motor, as set forth above, to have the cylinders immersed or submerged into the water jackets from above and supported independently thereof, there being no mechanical connections or insulating joint between the water jacket and cylinders throu'ghout the piston travel whereby the above noted advantages in construction and operation are obtained. In accordance with this feature of my invention I provide a se arate and distinct elongated valve 23 or the reception of the individual cfiiiders, the water jackets 22 being secured in a conventional manner to the valve cage 23, and the individual cylinders 25 being securely anchored directly to the valve cage 23 and maintained in spaced relation with the jackets 22 throughout the length of the piston travel. Each pair of jackets 22 has cast therewith at the upper end a shoulder as a securing means for attachment to the Al fl cage 23, this shoulder merging into a web or seat 24 bringing the adjacent pairs. This web 24 not only serves as a seat for the Cage but also strengthens and stiffens the jacket and crank case structure. The cylinders 25 are formed with integral heads 26 and are preferably fastened to the cage 23 b means of a screw threaded connection. or this purpose the valve ca'ge is provided with shallow pockets or chambers for the reception ot' each of the cylinder heads and their pockets are internally screw threaded for cooperation with the externally threaded upper portions of the cylinder. The threaded portions of the cylinders extend downwardly only for a short distance and are expanded as indicated to give the required valve space in the cylinder head for maximum power and speed. The walls of the threaded ortion and also the head may be of a slig itly thicker and heavier construction than the remainder of the cylinders. The valve cage is provided with an ample cooling chamber or space 28 for the circulation therethru of a suitable cooling or heat absorbing fluid. Communication is established and maintained between the water jacket chamber and this Valve cage chamber by means of openings 29 cast or otherwise formed in the valve cage. This construction forms a three-part assembly comprising the water jackets and the crank case, the valve cage and the individual cylinders, the water jackets and the valve cage bein directly connected and secured to each ot er by bolts 30 and the cylinders being maintained out of engagement with the water jackets and secured directly to the valve cage. These cylinders may be provided with radiating fianges 31 around the exterior thereof which also promote the transfer of heat energy. These cylinders are also provided adjacent their lower ends with external cylindrical anges 32 which cooperate with similar flanges 33 on the interior of the water jackets, together with suitable piackin'g therebetween, to seal the water jac ets or chambers from the interior of the crank case and against the entr of oil thereinto. By this construction an assembly the cylinder bodies 25 are free from mechanical engagement with the jackets 22 and according y are unaffected by the lcontraction and expansion thereof. The. cylinders therefore maintain their cylindrical shape independently of the jackets and bindings between the pistons and the cylinders due to distortion from the cylindrical shape is avoided. The cylinders are free from mechanical engagement with their supports throughout the piston travel, only the clearance space or combustion chamber of the cylinders being attached to the valve cage. The combustion chamber walls including the head 26 may therefore be made as thick as required to form a rigid connection with the support or cage without a corresponding increase in the bore of the cylinder or corresponding increase in the cylinder walls. Furthermore, the c linder may be expanded at its upper en and the head 26 may be made just as large as is desired to accommodate the required number of valves therein or value of the required dimensions for the rapid induction and eduction of the gases. Rapid intake and exhaust is especially important in the high speed and high powered engines used on aircraft and this construction enables the provision of the maximum valve space required for this purpose independently of the cylinder bore and thickness of the cylinder bore. A further advantage is that the thrust is transmitted directly to the cylinder head and valve cage the lower end of the cylinder being unattached to the motor frame work, and consequently there being no longitudinal strains set up in the cylinder bodles 25 to cause distortion thereof or cause them to rip at the base.

The motor illustrated is of the valve-inhead type and each cylinder head 26 is provided With a plurality of Valve openings therein with the usual valve seats formed around the openings. In the specific embodiment illustrated there are illustrated four valves for each cylinder, one pair of Valve openings 34 being the intake valves and the other pair 33 being the exhaust valves. These valves are symmetrically arranged around the. center of the cylinder hea as is usual in this art. The cylinders are initially formed with their heads slightly beveled or convexed outwardly as is indicated in Fig. 8 and when they are screwed home into the valve cage chambers 27 these convexed heads are caused to flatten out as indicated in Fig. 9, it being understood that the convexity of the cylinder heads need only be slight to accomplish the purpose intended. By means of this construction and assembly a good firm contact is produced between the cylinder head 26 and the valve cage which contributes toward efficiency in coolin In order to procure a moreperfect and rmer contact between the cylinder heads 26 and the valve cage and to maintain such contact under all conditions of service I provide each cylinder head 26, preferably integral therewith, with a tightening stud 36, these studs being conveniently located in the ample space provided in the center of the head 26 by the multiple valve arrangement. These studs 36 in the assembled position of the cylinders project u wardly thru openings 37 formed in the ottom wall of the valve cage and suitable clam ing nuts 38 engage the upper ends o the studs i Other o ings receivin the closing plugs 39. It has been found t at this construction affords at all times and during prolonged operating periods a thorough thermal connection between the cylinder heads and the valve cage.

enings are also formed in the upper wal of the cage which are closed by plugs 39 for affording access to the interior chamber thereof.

As above indicated each valve cage is integrally formed and preferably extends throughout the cylinder jackets of each bank. Above each cylinder this cage is provided with four openings 40 in alignment with the valve openings 34and 35 vfor the reception of the guides 41 thru which pass the valve stems 42. Each air of intake and exhaust valves is provide with a common yoke 43 to which are fixed the valve stems 42. Around the uide openings there are provided cylindrical chambers 44 (cast with the cage) for the reception of the valve actuating springs 45 and 46, these springs being in duplicate and concentricall arranged with respect to each other. 'lyhe inner valve spring 45 is of smaller dimensions than the outer stpring 46 as indicated in Fig. 12 and both o these s rings engage at their outer ends a collar 4 which is securely fastened to the upper end of the valve stem 42 whereby the yoke 43 is urged upwardly together with a valve stem 42 until the valves are caused to engage the valve seats. The valve cage 23 is provided with a cylindrical chamber 48 intermediate each set of valve stem guides 41, this chamber 48 bein prolonged upwardly by means of a cylin rical meinber 49 lprojecting upwardly toward the yoke 43. T is serves as a guide chamber for the cylindrical guide 50 fixed to the under side of a yoke 43 intermediate its ends. This construction insures an accurate alignment of the yoke and the cooperating parts. A compression spring 51 may be disposed within the cylindrical guide 50. This spring engages the bottom of the chamber 48 to assist the springs 45 and 46 in urging the yoke and valves upwardly in the path of the actuating cam 52 carried by the cam shaft. There are rovided two cam shafts for each bank o c linders, one of these cam shafts 53 being isposed above and in alionment with the intake valves and the other cam shaft 54 being similarly arran ed with reference tothe ex iaust valves. By aving a separate cam shaft for the intake and exhaust valves the' setting and timing of the intake valves may be accomplished independently of the timin of the exhaust valves and vice versa.

of cooperating flanges and bolts 74.

is contributes to a more accurate adjustment and setting of the valves. These cam shafts 53 and 54 are journalled in a plurality of bearing standards 56, each standard 56 being provided with feet 57 for attachment to the top of the Valve cage. The bearings are conveniently secured to the top of the cage by means of lscrew bolts 58 passing thru the feet 57 and en aging openin s formed in the top of the va ve ca e. Eae li bracket 56 is transversely arrange with reference to the cam shafts and carries a bearing for each thereof. The bearings are split in a plane coincident with the axes of the shafts and the up er half or cap 59 of the bearin is secure by the standard 56 by means 0% a pair of bolts 60 on the ends thereof and also by means of a centrally disposed screw bolt 61 as indicated in Fig. 15.

The above described mechanism including the cam shafts is entirely enclosed by means of an elongated casing or hood 63; this casing being preferably of a light material, such for instance as aluminum or alloy. This hood 63 may be secured to the valve cage by means of a plurality of bolts 64 indicated in Figs. 1 and 10. For the purpose of inspection or for other reasons this casing 63 may be provided with inspection openings which receive enclosing plugs 65. The casing is also provided with'openings for the reception of the air )ump 66, this pump being driven or actuated y an eccentric 67 fixed to the intake cani shaft 53.

The motor illustrated herein is of the geared down type and is adapted to drive a propeller which is mounted on a shaft 70, this propeller shaft 70 being mounted substantial y in alignment with the V formed by the two banks of cylinders. This shaft 70 is conveniently geared to the crank shaft 21 by means of a pair of gears 71 and 72, the latter being fixed to a right hand end (Fig. 1) of the crank shaft by means of bolts 73, passing thru cooperating flanges formed integrally of the ear andthe shaft. The gear 71 is similarly xed to the shaft 7() by niejins or accommodating these reduction gears the upper half of the crank case has cast therein a ear chamber 75, the inner wall of this cham er being indicated at 76, and the outer wall at 77. There is also formed integrally with the crank case and with the walls 76 and 77 a pair of aligned lower bearings 78 and 79 for the reception of a propeller shaft 70, the bearings 78 being the inner bearings and the bearings 79 being for the outer end of the shaft. Similarly there is formed integrally with the walls 76 and 77 a air of aligned upper bearings for the right hand end of the crank shaft, the inner of these bearings being designated at 80 and the outer at 81. By this construction there is formed integrally with the crank case for each of the shafts a pair of aligned bearings, the bearings of each pair being separated from each other by the transverse gear chambers 75. The bearings 78 and 79 may be provided with the usual liners 78 and 79 and in like manner the bearings 80 and 81 are provided with liners 80' and 81. .The propeller shaft bearings are split horizontally. the upper halves 78 and 79 and preferably formed integrally (cast) with a bearing cap 82. This bearing cap 82 may thereby be reinoved together with both of the upper bearings as a unit to permit the insertion of or the removal of the shaft 7.0 with its gear 71 from an assembled position. The lower half of the bearings for the crank shaft which cooperate with the upper bearings 80 and 81 are indicated Vat83 and 84 respectively. These lower hearings 83 and 84 are fixed to the upper half of the crank case by means of bolts 85, one on either side of the shaft, and in like manner the cap 82 with its pair of aligned bearings is fixed to the upper half of the crank case by means of its bolts 86. The cap 82 is also provided with another securing bolt 86 which passes thru a lug formed on the inner end thereof in alignment with the propeller shaft and enters a screw threaded pass formed on the crank case. In order to provide an absolutely rigid structure on the right hand end of the crank casing which carries the propeller stub shaft and the reduction gears, I provide means for attaching the cap 82 directly to the lower bearings 83Y and 84. For this purpose there are formed a number of vertical openings thru the cap 82, the bearing supports 78 and 79 and the lower bearings 83 and 84, these openings being in alignment with each other and adapted .to receive the clamping bolts 87 and 88. In the specific instance illustrated there are two of each of these bolts and they are provided with screw threaded valves 87 and 88 which engage with similarly threaded openings in the bearings 80 and 81. At the point where the bolts enter the bearings 78 and 79 they are provided with external screw threads for the reception of nuts 89 and 90. These bolts are also provided on their ends with screw threads for the reception of clamping nuts in the usual'nianncr. By this construction the walls forming the reduc-tion gear chamber and the hearings of the crank shaft and the propeller shaft are formed into a rigid` structure for securely withstanding the stresses and strains set up in the large torque transmitted between the crank shaft and the propeller shaft, the bolts 87 and 88 transinittiii the thrust directl from the bearings o the vpropeller sha t to the bearings.

of the crank shaft. The walls 76 and 77 of the reduction gear Chamber are provided with vertical stifl'ening flanges which serve to strengthen this part of the crank case. The feature of forming both the inner and outer bearin s of the propeller shaft integral with the crank case insures a perfect alignment of these bearings and their shafts under the most rigid conditions in service and the construction embodying the removable cap 82 simplifies and greatly facilitates the assembly of the shafts and the reduction gears. For instance, either the crank shaft 21 or the propeller shaft may be assembled in a osition or removed therefrom independent y of the other, it being noted that the propeller shaft together with the reduction gear 71 may be removed from its operative position by simply removing the cap 82, this cap, as heretofore set forth, being secured to the crank case by the bolts 86, 86', 87 and 88. There are also provided the aligning pins 91 for the removable ca 82. i

In the usua manner the upper half of the crank case is provided with downwardly eX- tendin bearing supports 92 extending throng out the length of the crank shaft, these supports having bearings carried by their lower ends which cooperate with the lower halves of the crank shaft bearings 20. A section of one of the crank shaft bearings complete is illustrated in Fig. 5, these being secured together by two pairs of bolts 93 and 93. A lubricantI duct 94 leads up to the lower half for connection with the branches 19.

Referring to the Figs. 1, 2, 6, and 7, the left hand end of the crank shaft case is rovided with a housing 95 which serves oth as a closure for the crank case and oil sump f and as a casing for enclosing the auxiliary drive mechanisms for the accessories hereinafter set forth. f This housing is adapted to fit onto the end of the crank case and ma be secured in position by means of a plura ity of securingbolts as indicated by the drawings. The housing is preferably formed (as by a casting) in one single piece and comprises an outer plate or main body 96, and a transverse enclosing web 97 which extends around the periphery thereof, the plate 96 t-aperin in width from a point midway of its Iength to the lower end. Formed integrally with this housing 95 is a pair of brackets 98 which extend out horizontally and carry the magnetos 99. On its lower end the housing is provided with a securing flange for the reception of a water circulating pump 100, this pump being securely fixed thereto in any convenient manner, as for instance by the securing bolts illustrated. The housing also has enclosed therein a pair of aligned bearing members 101 and 102 (preferably formed integrally therewith). The bearing 102 is adapted to receive a vertically disposed shaft of a circulating puin 99 whereas the bearing 101 has journalle therein a vertical shaft 103. The shaft 103 is adapted to be driven from the crank shaft 21 by means of a pair of intermeshing bevelled gears 104, and any convenient means may be provided lfor coupling the circulating pump shaft in alignment with the vertical shaft 103. This Vertical shaft 103 is also provided at its lower end with a bevelled gear 105 which intermeshes with a similar gear 106 on the shaft of the lubricating pump 15. The upper end of the housing 95 1s provided with an opening in alignment with the bearings 101 and 102 and is adapted to receive therein a bearing 106 in which is journalled the upper end of wardl the shaft 102. Near the upper end of the housing 95 and on the inner side thereof above the V there 'is provided an intake 107 whereb the oil sump may be replenished with lu ricant sup ly. The bearing 101 is carried by the vertically disposed web 101 bridgin the transverse web 97 and this web 101 is Joined to the plate 96 by means of a substantially horizontal rib 97. Similarly the bearing 102 is formed with an integral shelf or bridge 102 bridging the webs 97. The housing is provided with an opening near 4the upper end thereof which may be closed by a plate 108.

The system ofdrive for the various accessories and the ropeller is indicated diagrammatically in fig. 16 wherein, as indicated, a pair of inclined shafts 109 extend upwardly from the upper end of the shaft 103 for drivin the cam shaft. A bevelled gear is provi ed onthe up er end of the shaft 103 which meshes wit similar gears 110 on the lower ends of the shafts 109. Each shaft 109 is geared directly to an exhaust cam shaft by means of a pair of inktermeshing gears 111, the larger of these two gears being directly fixed to the ends of the cam shafts. Each shaft 109 is provided with a shaft housing 112, the lower end thereof being provided with a bearing 113 which fits into a corresponding opening 114 formed in the upper end of the housing 95. The upper end of the housing 112 is enlarged as at 112 to conform in sha e to the expanded or enlarged end of the e ongated casings 63 which encloses the valve mechanism and carries a bearing for the upper end of the shaft 109 as indicated in Fig. 2. It is noted that the shafts 109 extend upat an anglle to the axis of the cylinders Fig. 2) w ich has been found to be a very satisfactory arrangement for the drive. Each bevel 110 on'the lower end of the shaft 109 may mesh with a bevel 115 which is coupled tothe end of the correspending ma eto shafts. The shaft 103 is a so provide on its extreme upper end with a bevelled ear 116 for driving an accessory 117 as ir instance a tachorneter,

the latter being carried by the upper end of the housing 95. Each intake cam shaft is driven directly from the exhaust cam shaft by means o a pair of herrin bone gears, these gears being split an the halves thereof, separated from each other as indicated. fIhe halves of these herring bone gears being denoted respectively by the numorals 118 and 119. By splitting the gears in this manner and separating the halves thereof as indicated, an arrangement is provided which compensates for slight inaccuracies in-the alignment of the shaft and gears and therefore avoids the obections to the* use of the rigid spur gear o the nonpllt herring bone type of gear. In Fig. 17 have illustrated diagrammatically how this automatic ad'ustment and compensation takes lace. he full lines indicate the position of) the shafts and gears when accuratel aligned, the axes X-X and'Y-Y of the s afts being parallel arranged and disposedin the same plane and the view being taken in the direction of this plane. In this aligned position the shaft and gear on the opposite side are hidden from view, and for purposes of illustration this shaftisimagined to take an unaligned position as indicated in dotted lines, the other shaft being assumed to remain in its former position. The dis laced gears are indicated at 118 and 119 respectively, and Y-Y indicate the axis of the displaced shaft, itbeing understood that the displacement is exaggerated for convenienc in illustration. The shafts being axially s iftable with reference to each other, as set forth above, it is a parent that such displacement of the s afts from the aligned position result in a relative axial shifting indicated at M, the extent of this shifting being determined by the lateral dis lacement of the shafts. This Vresults in the teeth remaining in drivin contact notwithstanding imperfect alignment and each of the gears 118 and 119 assumes its share of the load at all times. The line of contact of a single pair of teeth is indicated at N in full line, showing the shafts in perfect alignment, and at N is indicated the line of contact of one of their teeth when out of ali ment. The line of contact N is shown slightly displaced from the line N for convenience in illustration but it is understood that the lines are coincident. In ordei` to bring out this compensation feature more clearly the shafts are illustrated as rockin relatively to each other about an axis, su stantially. midway of the gears 118 and 119, which is an aproximate indication of what takes place. he gear teeth remain in contact throughout their operative' surface, point c ontacts and the consequent uneven wear bein entirely avoided. The helical teeth`N are illustrated as being cut substantially at 45 degrees to the vface of the gears, but in practice the angle with the face is slightly less than 45 degrees. The gearing arrangement forms a very satisfactory drive for the cani shafts in that a smooth and even drive is obtained for actuating the valves under severe service conditions. Furthermore this type of gearing between the two cam shafts insures, as set forth above, the proper axial position of'the intake cam shaft. at all times since this shaft is held in intermesh with the reversed helical gea-rs on the exhaust cam shaft.

For leading the fuel charges to the intake chambers there are provided the intake manifolds 121, in the specific instance shown there being one intake for each set of three cylinders of a bank. These intakes 121 cooperate with the opposite intakes 121 to carry a duplex carburetor 122 therebetween. Each carburetor of the duplex unit therefore supplies three cylinders, in the specific embodiment illustrated there b'eing two duplex carburetors forthe twelve cylinders. Each intake manifold 121 has three pairs of branches 124, the branches of a pair leading to corresponding intake chambers 125 formed in the valve cage and in turn leading to the combination chamber thru the intake valves. The passage leading from the carburet-ors and including the intake chambers 125 designed with a view to obtaining a free 'and unobstructed flow of the fuel to the c inders. The fuel charges are led upwar ly from the carburetors thru Ypassages 126 'formed in the casin 127A and Vregistering with the intake manlfold. The casing 126 is provided with inlet and outlet connections 128 and 129 for the circulation of the cooling water therethru and around the fuel passages 126. Suitable mufiers 130 may be provided for taking care of the exhaust from the engine, these being suitably attached to the exhaust outlets 131 as indicated in Fig. 2.

Double ignition is employed, as is usual in aeronautical motors, each cylinder being provided with two spark plugs 132 for this purpose. These lugs are transversely disposed and pass t ru screw threaded openings 133 (Fig. 13? Valve ca e, the wal s of these openings being worked y the cooling fluid circulating in the valve cage chamber28. The threaded portions of the cylinders are provided with openings registering with the passages 133 whereby the plugs project into the combustion chambers.

Each bank of, cylinders is provided with a tapered water'` manifold 135 which has branches 135 leading thru passages formed in the intake manifold 121Y these passages the anch' intakes 124. The branches 135 and the connecting passages thru the intake which are cast in the being formed in bosses or bridges between.

manifold leadto the connections or openings 136 which in turn lead to the valve chamber 28. At the bottom of the water jackets each pair is provided with a connertion 137 and these connections 137 are in turn in communication with the bottom water manifold 138. It is understood that these manifolds are to be properly connected with the water circulating pump and the radiator (not shown). As above indicated the lubrication is obtained by forced lubrication by the pump 15. The crank shaft is hollow1 and is provided with the lubricant supply ducts 141 leading from the shaft bearing 2() to the connecting rod bearings 142. The bearings 80 and 81 and the propeller shaft bearings are provided with coni- ,lminicating ducts 143 (Fig. 1) which supply the propeller shaft bearings with lubricant'.

A duet 144 leads downwardly from the pro- 1 peller bearings and has its outlet playing on the peripheries of the gears 71 and 72 at their point of engagement whereby the reduction gears are kept well lubricated.` An

intake or breathing tube 145 may be pro- `f vided in the removable cap 182.

In accorda-nce with the requirements of the patent statutes I have set forth in the specific ina-nner required thereby one complete embodiment of my motor but it is nnf derstood that my invention is capable ol assuming other forms than that illustrated and that the claims hereto annexed are not to be limited to the specific devices shown except as is specifically recited therein, but are to be given a construction commensurate with the scope of the invention due regard being had to a considera-tion of the prior art.

What is claimed is:

1. In an internal combustion engine, ,the combination of a cylinder support having a recessed cylinder head seat thereon, a cylnder having an integral head for engagement in said recesses, means for securing said cylinder to said support and a stud formed on the cylinder headfor attachment to the cylinder support independently of the supporting means.

2. In an internal combustion engine, the

combination of an aluminum cylinder head having a cylinder head pocket and seat therein, a cylinder having an integral head, and a stud formed integrally with the head, means for securely anchoring said cylinder' within said pocket, and means for attaching said stud independently to said cylinder head for maintaining thermal contact between the head and said seat..

3. In an internal combustion engine, the combination of an aluminum valve cage having a screw threaded pocket therein for the reception of a cylindenacylinder haring an integral head-and having external screw threads thereon, whereby the same may be screwed home into said screw threadllt) adapted to en age said seat, said head having an inte ra stud thereon, means forsecurely attac ing said stud to said cylinder support, 'whereby the cylinder head is maintained in contact with the c linder support, and Water jackets independent of said cylinder, to which the cylinder supports are directly attached.

5. In an internal combustion engine, the combination of a crank case having cylinder Water jackets formed integrally therewith, a valve cage adapted to be attached directly to said water jackets, said valve cage having ockets therein for receiving the cylinder eads, cylinders having heads formed integrally therewith and ada ted to be anchored in said pockets, said cy inders having studs formed centrally on their heads and means for attaching said studs to said valve cage and drawing the cylinder head tightly againstthe valve cage for the purpose set forth. v

6. In an internal combustion engine, the combination of a crank case having c linder jackets formed integrally therewit said jackets having securin flanges on their upper ends, a valve ca e aving a complementary flange adapte to be lsecured to said first named flange, said valve cage having a plurality of screw-threaded ockets therein for receiving the cylindereads, a plurality of cylinders havin integral heads thereon and having screw t reads on the exterior thereof whereby the cylinders may be individually screwed home into said screwthreaded pockets, said cylinder head having studs formed integrally thereon, and means for attaching said stud tosaid valve cage and drawing the cylinder head tightly against said valve .cage for the purpose set forth. I f

7. In an internal combustion engine, the combination of -a cylinder support having a ocket with a seat therein for lreceiving a cy inder head, a cylinder having an inte-- gral head for attachment to sai Iup ort, means for anchoring said cylinder cad within said pocket, and additional means for maintaining said cylinder headl in thermal contact with the cylinder head support for the purpose set forth.

8. In'an internal combustion engine, the

combination of an aluminum cylinder support having a screw-threaded pocket therein for receiving a c linder head, a cylinder having an integral ead and screw threads on the exterior thereof, whereby the cylinder may be screwed home into said screwthreaded pocket, and means for drawing said cylinder head tightly against the valve c amber and maintaining thermal contact therebetween for the pur ose set forth.

9. In an internal com ustion engine, the combination of a valve cage havin a seat thereon for receiving a cylinder h a cylinder having an integral head, said head having three or more valve openin distributed around its center and also. aving a stud formed integrally thereon adjacent to the center, means for anchoring said cylinder against the seat on said valve cage and means for securelyk anchoring said stud to said valve cage for the' purpose forth.

10. In an internal lcombustion engine, the combination of a valve cage having a cylinder head seat thereon and a pluralit of valve openings therearound, a c .linder aving an integral head and a plura ity of openings therein complementary, to the openings in said valve cage seat, means for anchorl ing said cylinder to said valve ca e .with their o enings in register, and aditional means or clamping t e center of said head to said valve cage, whereby the cylinder head is maintained in thermal engagement with the cylinder head seat.

11. In an internal combustion engine, the combination of a valve cage 'having a pocket therein and a' plurality of valve openings around the bottom of said pocket, a cylinder having an inte al head for entering into said pocket, sai cylinder head having a plurality of valve openings complementary to the. valve o enings of the valve cage, means for anc oring ysaid cylinder head within said pocket and additional means for clampin cage an maintaining the saine in thermal contact therewith for the purpose set forth.

12. In an internal combustion engine, the combination of an aluminum valve cage having screw-threaded pockets therein and a said cylinder head to said valve iio plurality of valve openings disposed around the center of each pocketa plurality of cylinders having integral heads, each head having a plurality of valve openings around its in said valve cage, said cylinders having screw threads on the exterior thereof, whereby the same may be anchored individually into said screw-threaded pockets with their openings in register, and each head havingv an integral stud projecting upwardly vfrom' center and complementary to the openings '1.29

against the bottoms ofthe pockets for the by the same may;l

purpose set forth.

13. In an internal combustion engine, the combination of an aluminum valve cage having screw-threaded pockets therein and a plurality of valve openings disposed around the center of.each pocket, a plurality of cylinders having integral heads, each head having a plurality of valve openings around its center and complementary to the openings in said valve cage, said cylinders having screw threads on the exterior thereof, whereby the same may be anchored individually into said screw-threaded pockets with their openings in register, and each head having an lntegral stud projecting upwardly from its center for entering into the corresponding opening in the valve cage and drawing the cylinder heads tightl against the bottoms of the pockets for t e purpose set forth, a plurality of cooling jackets surrounding sa1d cylinders and adapted to be secured to said valve cage independently thereof.

14. In an internal combustion engine, the combination of an aluminum valve cage having screw-threaded pockets therein and a plurality of valve openings disposed around the center of each pocket, a plurality of cylinders having integral heads, each head havmg a plurality of valve openings around its center and complementary to the openings 1n said lvalve ca e, said cylinders having screw threads on t e exterior thereof, wherebe anchored individually into said screwreaded pockets with their openings in register, and each head having an integral studprojecting upwardly from its center for entering into the corresponding opening in the valve cage, and means for securely clamping said studs to said v alve cage and drawing the cylinder heads tightly against the bottoms of the pockets for the purpose set forth, and a crank case having a plurality of cooling jackets formed integrally therewith and surroundin said cylinders, and means for independent attaching said valve cage to said cooling jackets for the purpose set forth.

15. In an internal combustion engine, in combination, a crank case, water jackets carried thereby, a valve cage mounted on the top of said jackets, said valve cage having seats thereon for receiving indivldual c linder bodies and a lurality of cylin er bodies having integral) heads ada ted to be clamped against said seats, saii cylinder heads being formed with a slight outward convexity for the purpose set forth.

16. In an internal combustion engine, in combination, a crank case, water 'ackets carried thereby, a valve cage attac ed to and mounted u on the upper ends of said jackets, said va ve cage having cylindrical pockets or chambers 1n register with'said jackets,

a plurality of cylinder bodies having their heads formed inte ally therewith, said cylinders being forme with their heads slightly convexed outwardly, and means for securely anchoring said cylinder bodies within said ockets and flattening out said convexed ead for the purpose set forth.

17. In an internal combustion engine, a cylinder assembly compxrising 'a valve ca e, said cage having cylin ical screw threa ed pockets or chambers formed therein, and a plurality of cylinder bodies with integral eads slightly convexed outwardly, said cylinders havingexternal screw threads on the upper end t ereof whereby they may be screwed home in said screw threaded ockets and their convexed heads Batten out.

In testimony whereof I hereunto ax my signature.

Y CHARLES B. 

